In optical telecommunication systems with signal transmission via optical fibers, the interaction of laser chirp, on the one hand, and fiber dispersion, on the other hand, leads to possibly substantial signal distortion which, in particular in the case of analog signal transmission (for example, AM-CATV) in the wavelength window around 1.55 .mu.m via standard monomode fibers, can restrict the range of such systems to a few hundred meters.
Laser chirp, that is to say the modulation-dependent frequency deviation of a laser, can be circumvented by the use of external modulators, but this entails an appreciable outlay. An attempt can be made to combat fiber dispersion, that is to say the wavelength-dependent spread of the signal propagation time in the optical fiber, by splicing in fiber pieces having a dispersion opposite to that of the standard fiber, but it is then necessary to accept an appreciable additional attenuation. A further approach to a solution is offered by electronic compensation measures; thus, an all-pass and a low-pass filter structure (with a varactor diode) for compensating the fiber dispersion by corresponding signal delays are known from ELECTRONICS LETTERS 27 (1991) 5 dated 28.02.1991, pages 421 to 423.
By contrast, the invention adopts a different approach for the purpose of electric compensation of signal distortion in an optical telecommunication system caused by laser chirp and fiber dispersion.